Impulsivity is a loose construct, and is often used interchangeably with behavioral disinhibition or behavioral undercontrol. The variable terminology may result from the fact that several different personality processes have been identified that lead to rash or impulsive acts. Historically, there has been no consistent, agreed-on understanding of the nature of the underlying disposition(s). As Depue & Collins (1999) put it, ‘impulsivity comprises a heterogeneous cluster of lower-order traits that includes terms such as impulsivity, sensation seeking, risk-taking, novelty seeking, boldness, adventuresomeness, boredom susceptibility, unreliability, and unorderliness’ (p. 495). There is a growing data-based consensus that there is no single personality trait that underlies the disposition to rash or impulsive action (Whiteside & Lynam 2001; Smith et al. 2007). Instead, recent models have described five different dispositions to rash action that are only moderately related to each other; the median inter-correlation among the five traits (which are described below) was 0.25 in a recent study (Cyders & Smith 2007; Cyders et al. 2007). Two of the five dispositions are emotion-based: positive urgency is the tendency to act rashly when experiencing
